I PHENYLHYDRAZINE 173 The base, which has a brown colour, is filtered and dissolved in hot spirit, with the addition of a few drops of concentrated « ammonia. Yield, about 8 grams. C0H6N:N.NHC0H6 + H.C0H4NH2.HC1 - C0H5N:N.C0H4.NH2 + CCH5NH2.HC1. I Properties.—Orange prisms ; m. p. 127°. , J Reaction.—Make a solution of 4 grams stannous chloride in 10 c.c. cone, hydrochloric acid, add 2 grams aminoazobenzene, J»' and boil for a few minutes. On cooling crystals of the hydro- / chlorides of aniline and ^-phenylenediamine separate out. 1 The liquid is filtered and washed with a little cone, hydro- ;" j, chloric acid to remove the tin salts. If the precipitate is ' \> dissolved in water and made alkaline with caustic soda, a '* mixture of liquid aniline and solid/-phenylenediamine is pre- \ cipitated, from which the former may be removed by filtering, washing, and draining on a porous plate. ^; C0HBN:N.C0H4NHo + "2SnCl2 + 4HC1= /> C0H5NH2 4- H2N.CGH4.NH2 + 2SnCl4. '* /-Phenylenediamine, when warmed with dilute sulphuric acid '' and potassium bichromate or lead peroxide, gives the odour of ji quinone (p.-192). After warming and cooling, extract with ether. flL The ethereal solution has a yellow colour. Decant the ether 1p extract on to a watch-glass and leave it to evaporate in the air. 'ft A deposit of microscopic yellow crystals remains. See Appen- * ,, diX) p. 286. ||* **\ PREPARATION 71. ^ Phenylhydrazine, C0H5NH,NH2 -,f E. Fischer, Annalen, 1878, 190, .167 ; Meyer, Lecco, Ber^ \\. ' 1883, 16, 2976 ; Meyer and Jacobson, Lchrlntch, 2, 305. ^ 20 grms. aniline. !\ ^ 200 „ (170 c.c.) cone, hydrochloric acid. ' * 20 „ sodium nitrite (in 100 c.c. water). ^ 120 „ crystallised stannous chloride (in 100 c.c. ^ cone, hydrochloric acid). . ?;' 1 |f* The aniline is dissolved in the concentrated hydrochloric k\( acid and cooled to o° in a freezing mixture. The solution of ' i (.